Manipulator head assembly

Abstract

A head assembly for a manipulator has an inner part, an intermediate part, and an outer part adapted to hold a tool. The inner part can rotate on the manipulator about an inner axis defined thereby whereas the intermediate part rotates on the inner part about an intermediate axis defined by the inner part and intersecting the inner axis at an acute intermediate angle open away from the inner part. The outer part rotates on the intermediate part about an outer axis defined by the intermediate part and intersection the intermediate axis at a point offset from the inner axis and at an acute outer angle open away from the intermediate part. In no position of head assembly can any of the pivot axes--inner, intermediate, or outer--be coaxial with any of the other pivot axes. The intermediate pivot and drive includes a shaft extending along the inner axis from the inner part. In addition there is another shaft extending along the intermediate axis in the intermediate part and gears rotationally couple the shafts. The inner and intermediate parts meet at a joint defining with the inner and intermediate axes an inner swivel plane substantially perpendicular to the intermediate axis. The outer and intermediate parts meet at a joint lying in an outer plane defining with the outer and intermediate axes an outer swivel plane substantially perpendicular to the intermediate axis and meeting the inner plant at an obtuse angle.

I claim: 
     
       1. A head assembly for a manipulator usable in combination with a tool, the assembly comprising: an inner part;   inner pivot means for supporting the inner part on the manipulator for rotation about an inner axis fixed relative to the manipulator and extending through the inner part;   an intermediate part;   intermediate pivot means for supporting the intermediate part on the inner part for rotation about an intermediate axis fixed relative to the inner part, extending through the intermediate part, and intersecting the inner axis at an acute intermediate angle having an apex at the inner axis and opening from the apex away from the inner part;   an outer part provided with a tool holder adapted to hold the tool;   outer pivot means for supporting the outer part on the intermediate part for rotation about an outer axis fixed relative to the intermediate part, extending through the outer part offset from the tool in the holder, and intersecting the intermediate axis;   inner drive means for rotating the inner part on the manipulator about the inner axis defined thereby;   intermediate drive means for rotating the intermediate part on the inner part about the intermediate axis and including a first intermediate shaft extending along the intermediate axis,   a bevel gear on the intermediate shaft,   means including another bevel gear supported on the inner part and meshing with the gear on the shaft for rotating the first intermediate shaft in the intermediate part about the intermediate axis, and   a stepdown transmission connected between the first intermediate shaft and the intermediate part for relatively slow rotation of the intermediate part relative to the first intermediate shaft; and     outer drive means for rotating the outer part on the intermediate part about the outer axis and thereby orbiting the tool about the outer axis, the outer drive means including an outer shaft extending along the outer axis,   a bevel gear on the outer shaft,   means including a second intermediate shaft and bevel gear centered on the intermediate axis and meshing with the bevel gear of the outer shaft for rotating the outer shaft in the outer part about the outer axis, and a stepdown transmission connected between the outer shaft and the outer part for relatively slow rotation of the outer part relative to the outer shaft.     
     
     
       2. The manipulator head assembly defined in claim 1 wherein the inner and intermediate parts meet at a joint defining an inner swivel plane substantially perpendicular to the intermediate axis. 
     
     
       3. The manipulator head assembly defined in claim 2 wherein the outer and intermediate parts meet at a joint lying in an outer plane defining an outer swivel plane substantially perpendicular to the intermediate axis and meeting the inner plane at an obtuse angle. 
     
     
       4. The manipulator head assembly defined in claim 1 wherein the intermediate part is generally trapezoidal and extends along a center axis intersecting the the inner, outer, and intermediate axes. 
     
     
       5. The manipulator defined in claim 1 wherein the first intermediate shaft is a tube shaft surrounding the second intermediate shaft of the outer drive means.